com.github.andyshao.nio.StringBufferReader Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of Gear Show documentation
Enhance and formating the coding of JDK
The newest version!
package com.github.andyshao.nio;

import com.github.andyshao.lang.GeneralSystemProperty;

import java.io.IOException;
import java.nio.ByteBuffer;
import java.nio.channels.ReadableByteChannel;
import java.util.function.Function;

/**
 * 
 * Title:

 * Descript:

 * Copyright: Copryright(c) Jun 22, 2015

 * Encoding:UNIX UTF-8
 * 
 * @author Andy.Shao
 *
 */
public class StringBufferReader implements BufferReader {
    /**
     * 
     * Title:

     * Descript:

     * Copyright: Copryright(c) Oct 25, 2015

     * Encoding:UNIX UTF-8
     * 
     * @author Andy.Shao
     *
     */
    public static class SeparateByStr implements Function {
        private final String key;

        /**
         * build {@link SeparateByStr}
         * @param key key
         */
        public SeparateByStr(String key) {
            this.key = key;
        }

        @Override
        public com.github.andyshao.nio.BufferReader.SeparatePoint apply(String t) {
            int index = t.indexOf(this.key);
            return new BufferReader.SeparatePoint(index , this.key.length() + index);
        }

    }

    private final ByteBuffer byteBuffer;
    private final ReadableByteChannel channel;
    private String encoding = GeneralSystemProperty.FILE_ENCODING.value();
    private Function findSeparatePoint = new StringBufferReader.SeparateByStr(GeneralSystemProperty.LINE_SEPARATOR.value());
    private volatile boolean hasNext = true;

    private String temp = "";

    /**
     * Build {@link StringBufferReader}

     * the capacity of {@link ByteBuffer} is 1024
     * 
     * @param channel the channel which could be readed
     */
    public StringBufferReader(ReadableByteChannel channel) {
        this(channel , 1024);
    }

    /**
     * Build {@link StringBufferReader}
     * 
     * @param channel the channel which could be read
     * @param bufferSize the capacity of {@link ByteBuffer}
     */
    public StringBufferReader(ReadableByteChannel channel , int bufferSize) {
        this.channel = channel;
        this.byteBuffer = ByteBuffer.allocate(bufferSize);
    }

    @Override
    public void close() throws IOException {
        this.channel.close();
    }

    /**
     * Get the encoding of channel's
     * 
     * @return the encoding
     */
    public String getEncoding() {
        return this.encoding;
    }

    @Override
    public boolean hasNext() {
        return this.hasNext;
    }

    @Override
    public String read() throws IOException {
        if (this.temp.length() == 0) {
            if (this.channel.read(this.byteBuffer) == -1) {
                this.hasNext = false;
                return null;
            }
            this.byteBuffer.flip();
            this.temp = new String(ByteBufferOperation.usedArray(this.byteBuffer) , this.encoding);
            this.byteBuffer.clear();
        }

        LOOP: while (true) {
            BufferReader.SeparatePoint point = this.findSeparatePoint.apply(this.temp);
            if (point.getSeparatePoint() == -1) {
                if (this.channel.read(this.byteBuffer) == -1) {
                    this.hasNext = false;
                    return this.temp;
                }
                this.byteBuffer.flip();
                this.temp = new String(ByteBufferOperation.usedArray(this.byteBuffer) , this.encoding);
                this.byteBuffer.clear();
                continue LOOP;
            } else {
                String result = this.temp.substring(0 , point.getSeparatePoint());
                this.temp = this.temp.substring(point.getNextStartSit());
                return result;
            }
        }
    }

    /**
     * Set the encoding of channel's
     * 
     * @param encoding the encoding of channel's
     */
    public void setEncoding(String encoding) {
        this.encoding = encoding;
    }

    /**
     * Set the {@link BufferReader.SeparatePoint} converter
     * 
     * @param findSeparatePoint the {@link BufferReader.SeparatePoint} converter
     */
    public void setFindSeparatePoint(Function findSeparatePoint) {
        this.findSeparatePoint = findSeparatePoint;
    }

}